itskrees

iTrader: (1)

Thank you! Car feels great apart from the idle issue. Very different animal than I'm used to. In regards to the firmware, how do I check for that? Also, is the idle rpm something I can do on my own without a wideband or bringing it back to the tuner?

That's closer to what I was expecting.. odd. I wonder what gives? I'm using the alternator from my 97. All sensors were transferred from my 97 onto the 99 motor, and is running off the 97 harness to the MSPNP. That reminds me, in the middle of the tune, I noticed two things in the engine bay - the IAT sensor fell out of the bung and the bung covering one of the holes in the intake also came off. My tuner assured me it didn't mess with anything, but now I'm curious if it may have affecting something drastically? I eventually ziptied the IAT to the intake so it wouldn't fall off, but the hole in the intake was left uncovered. He said as long as it's not the intake manifold it should be fine. I'm assuming he's saying its okay because I deleted the MAF sensor? You can see the hole here by the coupler that connects the intake pipe to the throttle body, and you can also see that the IAT sensor actually fell out of the bung when the picture was taken since it can't be seen in the middle of the intake pipe:




AFAIK, the pistons were 11:0:1 but they shaved them down to make 10:5:1. Either way, its more compression than both the NB1 and NB2 motors.

Oh, I thought I recalled reading somewhere about Savington mentioning the need for different lines/fuel pump/etc..to do it "properly". I honestly haven't done enough research to determine what that entails or if it's overkill for a car that only sees the track 5 months out of the year.

codrus

The megasquirt runs speed/density, which doesn't rely on all of the intake air passing through a sensor in order to fuel it properly. A hole in the intake pipe ahead of the throttle body just means you're getting unfiltered air (well, it could in theory also change the resonance of the intake, but I doubt that's a significant factor here).

Doing E85 pretty much requires new injectors, because you'll need something like 60% more fuel than you would with gasoline and it's very unlikely you have that much headroom in the injectors you already have. The stock fuel pump, OTOH, has a lot more headroom than the stock injectors, so there might be enough for E85 on a naturally aspirated engine. For a high power turbo E85 build you need bigger fuel hard lines, but for an NA engine that's overkill.

Doing it "properly" means swapping out all of the fuel related components for ones that are actually rated for E85, adding a flex fuel sensor and an ECU that can read it, etc. That's a lot more work than is strictly required.

The big downside to E85 from what I can see is that it's not available at the race track (at least, not at any of the tracks around here). That means I'd need to take it there with me, and for a 2-day track weekend I'd probably need a 55 gallon drum of it, which gets into things like DOT hazmat transportation regulations and other icky stuff.

As for the ECU, timing precision is pretty important. If the spark timing is off by a degree or two, then you wind up needing to back the timing off by that degree or two as a safety margin. The NB's 4-tooth crank angle sensor is a lot more precise than the NA's cam angle sensor (no stretchy belt in between), but a 12-tooth wheel is even better. More teeth lets the ECU measure the engine speed over a short period of time, giving it a more accurate view of the rate at which the RPM is rising. How much power does that translate into on an NA build? I have no idea.

--Ian

Lincoln Logs

iTrader: (1)

60% more fuel for a car like this is a bit much , reality is around 10-15% more fuel in cruising and ~30% more at WOT. Stock injectors do not flow enough, you might be able to get there with 60psi of fuel pressure but your injectors might be maxed. It's just as cheap to get some RX-8 injectors from Rockauto for $35ea.

From what I've seen from people using it in N/A Miatas it's around 5 gallons of E85 for one session. If you're towing it's not problem to fill the tank and throw some 5 gal jugs in the bed of the truck.

This is true but I don't think it translates into much of a loss, if any, at these power levels. From what I've seen on my car it hasn't held me back yet. However, the more exotic the engine becomes I would see this as a way of keeping your motor safe if you run the tune on the edge.

Fireindc

iTrader: (13)

If you don't know, you are probably on the standard firmware. You NEED hi-res code on a ms1 to be able to idle smoothly, it is a huge difference. I'm not 100% sure off the top of my head how to check the firmware, just do some googling and it's all pretty easy. Actually, i know one easy way. When you pull up your injector pulsewidths in MS, do you see something like "2.1" or "2.15"? If you just see x.x it's on the standard firmware, if you see x.xx you are on hi-res. The hi-res code increases your injector resolution for more fine tuning, which results in less fluctuation and "hunting" for idle.

There is a thread somewhere on here that i followed to flash my ms1 with hi-res, and it made all the difference in the world with my idle quality.

You can adjust your idle RPM and other settings via MS as well, so try raising the idle and switching to hi-res code and you will be set.

itskrees

iTrader: (1)

Hey thanks for the great info man! Did simply flashing the firmware do the trick? Or did you still have to adjust the settings yourself once the increased resolution was made available? If it's the latter, I don't know the first thing on how to do that.

Fireindc

iTrader: (13)

You just need to flash the firmware and your tune should still be 90% of the way there. You of course will want to fine tune it again after getting the higher res firmware so that you can take full advantage of it.

In my case i had not a clue how to flash firmware, but there is a thread somewhere here on it and I just followed that. It was actually pretty easy, despite being a somewhat daunting task on paper.

Re-tuning is SUPER easy, just look at your AFR at idle and you can adjust your VE to get the afr at idle perfect. Once you have your idle dialed in, you can use TunerStudio's VEAL (ve analyze live) feature to auto tune in your fuel map, just make sure you have good target afrs and your wbo2 is accurate.

I'm not saying this will 100% fix your problems, but it definitely fixed my "hunting" idle i'd have from time to time.